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1. Bayesian optimization of nanophotonic electromagnetic shielding with very high visible transparency

   https://doi.org/10.1364/OE.468843  

   Li, Mingxuan; McCourt, Michael_J; Galante, Anthony_J; Leu, Paul_W (August 2022, Optics Express)

   Transparent electromagnetic interference (EMI) shielding is needed in many optoelectronic applications to protect electronic devices from surrounding radiation while allowing for high visible light transmission. However, very high transmission (over 92.5%), high EMI shielding efficiency (over 30 dB) structures have yet to be achieved in the literature. Bayesian optimization is used to optimize different nanophotonic structures for high EMI shielding efficiency (SE) and high visible light transmission ( ${\stackrel{¯<\#comment/>}{T}}_{vis}$). Below 90% average visible light transmission, sandwich structures consisting of high index dielectric/silver/high index dielectric films are determined to be optimal, where they are able to achieve 43.1 dB SE and 90.0% ${\stackrel{¯<\#comment/>}{T}}_{vis}$. The high index of refraction dielectric layers reduce absorption losses in the silver and can be engineered to provide for antireflection through destructive interference. However, for optimal EMI shielding with ${\stackrel{¯<\#comment/>}{T}}_{vis}$above 90%, the reflection losses at the air/dielectric interfaces need to be further reduced. Optimized double sided nanocone sandwich structures are determined to be best where they can achieve 41.2 dB SE and 90.8% ${\stackrel{¯<\#comment/>}{T}}_{vis}$as well as 35.6 dB SE and 95.1% ${\stackrel{¯<\#comment/>}{T}}_{vis}$. K-means clustering is utilized to show the performance of characteristic near-Pareto optimal structures. Double sided nanocone structures are shown to exhibit omnidirectional visible transmission withSE = 35.6 dB and over 85% ${\stackrel{¯<\#comment/>}{T}}_{vis}$at incidence angles of 70 ${}^{\circ <\#comment/>}$. 

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2. Bell state analyzer for spectrally distinct photons

   https://doi.org/10.1364/OPTICA.443302  

   Lingaraju, Navin_B; Lu, Hsuan-Hao; Leaird, Daniel_E; Estrella, Steven; Lukens, Joseph_M; Weiner, Andrew_M (March 2022, Optica)

   We demonstrate a Bell state analyzer that operates directly on frequency mismatch. Based on electro-optic modulators and Fourier-transform pulse shapers, our quantum frequency processor design implements interleaved Hadamard gates in discrete frequency modes. Experimental tests on entangled-photon inputs reveal fidelities of $\sim <\#comment/>98\mathrm{\%<\#comment/>}$for discriminating between the $|{\mathrm{\Psi <\#comment/>}}^{+}⟩<\#comment/>$and $|{\mathrm{\Psi <\#comment/>}}^{-<\#comment/>}⟩<\#comment/>$frequency-bin Bell states. Our approach resolves the tension between wavelength-multiplexed state transport and high-fidelity Bell state measurements, which typically require spectral indistinguishability. 

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3. Braid group action and quasi-split affine 𝚤quantum groups I

   https://doi.org/10.1090/ert/657  

   Lu, Ming; Wang, Weiqiang; Zhang, Weinan (October 2023, Representation Theory of the American Mathematical Society)

   This is the first of our papers on quasi-split affine quantum symmetric pairs $(\stackrel{~<\#comment/>}{\mathbf{U}}\left(\stackrel{^<\#comment/>}{\mathfrak{g}}\right),{\stackrel{~<\#comment/>}{\mathbf{U}}}^{\mathrm{ı<\#comment/>}})$, focusing on the real rank one case, i.e., $\mathfrak{g}={\mathfrak{s}\mathfrak{l}}_3$equipped with a diagram involution. We construct explicitly a relative braid group action of type $A_2^{\left(2\right)}$on the affine $\mathrm{ı<\#comment/>}$quantum group ${\stackrel{~<\#comment/>}{\mathbf{U}}}^{\mathrm{ı<\#comment/>}}$. Real and imaginary root vectors for ${\stackrel{~<\#comment/>}{\mathbf{U}}}^{\mathrm{ı<\#comment/>}}$are constructed, and a Drinfeld type presentation of ${\stackrel{~<\#comment/>}{\mathbf{U}}}^{\mathrm{ı<\#comment/>}}$is then established. This provides a new basic ingredient for the Drinfeld type presentation of higher rank quasi-split affine $\mathrm{ı<\#comment/>}$quantum groups in the sequels. 

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4. Uniform Lech’s inequality

   https://doi.org/10.1090/proc/16304  

   Ma, Linquan; Smirnov, Ilya (February 2023, Proceedings of the American Mathematical Society)

   Let $(R,\mathfrak{m})$be a Noetherian local ring of dimension $d\ge <\#comment/>2$. We prove that if $e\left({\stackrel{^<\#comment/>}{R}}_{red}\right)>1$, then the classical Lech’s inequality can be improved uniformly for all $\mathfrak{m}$-primary ideals, that is, there exists $\mathrm{\epsilon <\#comment/>}>0$such that $e\left(I\right)\le <\#comment/>d!\left(e\right(R)-<\#comment/>\mathrm{\epsilon <\#comment/>})\mathrm{\ell <\#comment/>}\left(R/I\right)$for all $\mathfrak{m}$-primary ideals $I\subseteq <\#comment/>R$. This answers a question raised by Huneke, Ma, Quy, and Smirnov [Adv. Math. 372 (2020), pp. 107296, 33]. We also obtain partial results towards improvements of Lech’s inequality when we fix the number of generators of $I$. 

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5. Demonstration of the DC-Kerr effect in silicon-rich nitride

   https://doi.org/10.1364/OL.432359  

   Friedman, Alex; Nejadriahi, Hani; Sharma, Rajat; Fainman, Yeshaiahu (August 2021, Optics Letters)

   We demonstrate the DC-Kerr effect in plasma enhanced chemical vapor deposition (PECVD) silicon-rich nitride (SRN) and use it to demonstrate a third order nonlinear susceptibility, ${\mathrm{\chi <\#comment/>}}^{\left(3\right)}$, as high as $(6\pm <\#comment/>0.58)\times <\#comment/>{10}^{-<\#comment/>19}{\mathrm{m}}^2/{\mathrm{V}}^2$. We employ spectral shift versus applied voltage measurements in a racetrack resonator as a tool to characterize the nonlinear susceptibilities of these films. In doing so, we demonstrate a ${\mathrm{\chi <\#comment/>}}^{\left(3\right)}$larger than that of silicon and argue that PECVD SRN can provide a versatile platform for employing optical phase shifters while maintaining a low thermal budget using a deposition technique readily available in CMOS process flows. 

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